Stack of spaced sheets

ABSTRACT

This disclosure relates to the manufacture of lites (glass sheets) which have at least a pair of thin spacers applied thereto which maintain the lites in spaced relationship when stacked upon pallets, wrapped and shipped. The spacers are preferably only partially adhered to the lites, either by weak bonding adhesive or electrostatically, and can be readily removed during end-use applications. The spacers are applied automatically during production runs of the lites, and the spacers are applied from above or from below relative to the path of travel of the lites.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the manufacture of lites (glass sheetsor glass panels) which are eventually stacked in relatively intimated,though spaced, relationship to each other.

2. Description of the Relevant Art

It is conventional to stand lites/glass sheets on edge substantiallyvertically and interleave a sheet of paper, such as craft paper, betweenthe sheets. Such sheets are generally stacked upon a pallet and areenclosed by a relatively strong polymeric/copolymeric film, such asrelatively transparent or translucent polyethylene film. The interleavedsheets of paper function to impede corrosion of glass, prevent scratchesand damp shocks, thereby safeguarding the glass sheets, which otherwisemay be broken or cracked by relative movement/collision therebetween, aswhen such stacked and palletized sheets are transported to an end user.

Interleaving a sheet of paper between glass lites has in the past beendone manually and is, therefore, time-consuming and costly from aproduction standpoint.

U.S. Pat. No. 4,807,743 acknowledges the function of such paper sheetsto impede corrosion of glass, prevent scratches, damp shocks and preventglass sheet/lite breakage. However, this patent also recognizes thatmoisture which is absorbed by such large paper sheets can createchemical reactions with the glass which produce paper stains on theglass surfaces. Wrinkle patterns from the paper sheets are said to betransferable to the lites thereby rendering the same less attractive.Glass quality is also said to deteriorate as a result of surfaceweathering of the glass sheets due to moisture absorption by the papersheets, particularly under high humidity conditions under which waterdroplets may form and drip upon the lites. This patent suggests as onesolution to these problems the same conventional utilization of craftpaper as spacer material, but associated therewith are bodies ofdesiccant material housed within an overwrap of the stacked glass. Theoverwrap is a polyethylene film having low water vapor transmissioncharacteristics. While this patent proposes solutions to severalproblems, its disclosure is silent with respect to the continuedconventionality of utilizing large sheets of paper as spacers betweenadjacent pairs of lites.

Another approach to protecting sheets of material against damage duringstacking or packaging is found in U.S. Pat. No. 3,385,462 which firstacknowledges the interposition of loose materials, such as straw, woolfiber and sawdust, between sheets of glass when they are packed fortransportation, or to interpose sheets of relatively soft material, suchas paper or corrugated cardboard. However, the patent goes on to statethat these methods do not prevent surface damage to the sheets which mayin some cases make them useless, particularly if they are of a very highquality glass or have been specially surface treated. This patentproposes the utilization of a plurality of spacing members, such as padsof polyurethane having coatings of pressure-sensitive adhesive on theopposite faces which contact the glass sheets. An alternative approachis the utilization of spacing members each having a head portion formedas a suction member and a stem portion which is relatively flat. Suchpads or spacer members are positioned between the glass sheets. Thesespacers are costly because of the intricate configuration thereof andthe amount of material associated with each, not to mention the highproductivity costs involved in manually locating a plurality of suchspacers between adjacent glass sheets.

U.S. Pat. No. 2,992,747 avoids the utilization of individual spacers ofany type, yet protects the surfaces of glass sheets that are stackedtogether for storage, shipment or other handling by spraying or applyingparting material, with or without filler, upon surfaces of the sheets tomaintain the same spaced when in stacked relationship. Such partingmaterial coatings adhere to the glass sheet surfaces and providesuitable space between adjacent surfaces of the stacked glass sheets.Problems associated with such protection involve air quality standardsduring application, but more importantly remains the end use task ofremoving the coatings incident to the utilization of the glass sheets.

U.S. Pat. No. 2,476,145 suggests electrostatically charging glass sheetsas they travel along a conveyor through the utilization of a silk clothroll. Each glass sheet is thereby electrostatically charged. Theelectrostatically charged glass sheets are conveyed through anatmosphere filled with wood flour which causes the particles of flour tobe attracted to the charged surfaces of the glass sheets in a relativelythin uniform layer. By negatively electrostatically charging the woodflour, the latter will be attracted and retained for a sufficient timeto achieve stacking and wrapping of the glass sheets.

SUMMARY OF THE INVENTION

The invention is directed to a novel method of manufacturing a stack oflites (glass sheets or plates) in spaced relationship to each other tothereby prevent damage, particularly during shipment. The lites aresuccessively fed along a first path of travel and thin spacers are fedalong a second path of travel with the paths of travel converging towardan area of merger at which the thin spacers are adhered to the lites.The lites are thereafter stacked with the thin spacers sandwichedbetween adjacent pairs of the lites.

The thin spacers are carried by a ribbon formed of first and secondrelatively narrow strips of material. First surfaces of the two stripsof material are in surface-to-surface abutting relationship, and aplurality of unending preferably circular cut lines are formedsubstantially through the first strip of material to set-off successivespacers which are carried by the second strip of material after removalof first strip waste material. Each spacer has associated therewithindicia means for activating a sensor to effect timed removal of thespacers from the second strip and the timed transfer thereof to anassociated lite. The sensor activating means is preferably a dark lineor bar of printed indicia associated with each spacer which isconventionally sensed to control ribbon feed in timed relationship withedge sensing of the conveyed lites. Preferably, at least two spacers areapplied to each lite with one spacer being applied relative to leadingedge sensing of the lite and the second spacer being applied responsiveto trailing edge sensing of the lite. After each lite has appliedthereto at least two such spacers, the lites are stacked upon a pallet,are appropriately wrapped in conventional film, and can be readilytransported absent deterioration or damage because of the protectionafforded by the spacers.

In further accordance with this invention, the relatively thin spacersare designed not only for spacing and thereby protecting the lites, butperhaps as importantly is the fact that the spacers can be readilyremoved incident to end use applications. For example, the lites can beglass shelves for refrigerators which are shipped from the litemanufacturer/fabricator in stacks to the refrigerator manufacturer. Eachthin spacer must be readily removed by the manufacturer or the eventualend user, namely, the retail purchaser. To the latter end the spacerseach include first and second surface areas which contact an associatedlite. The first surface area of each spacer is in substantially adheringrelationship to the lite, while the second surface area is insubstantially nonadhering relationship to the lite. Therefore, theadhered first surface areas function to retain the spacers in positionupon the lites during fabrication, stacking and shipment, while thesecond surface areas permit the spacers to be readily grasped andremoved from the lites, either by the end use manufacturer or the enduse retail user.

Preferably, each first surface area of each spacer possesses eitheradhesive characteristics or static cling (electrostatic)characteristics. In the first case, each spacer is preferably made ofpaper and includes on its first surface area a relatively weak bondingadhesive, while the second surface area excludes adhesive.Alternatively, both the first and second surface areas may be providedwith a weak bonding adhesive, but the second surface areas are coveredwith a very thin covering, such as a thin piece of paper. In such case,the thin piece of paper or tab prevents the second surface areas fromadhering to the lites and facilitates subsequent end use removal.

In lieu of the paper spacers, the spacers may also be made of materialpossessing static cling characteristics (electrostatically adherent toglass). Static cling vinyl or similar polymeric/copolymeric material ispreferably utilized, and absent other provisions, each such static clingvinyl spacer readily adheres to an associated lite. However, theadherence is so relatively dramatic that difficulties could beencountered unless otherwise provided for, as, for example, difficultyof end-use removal, difficulty of glass separation, and the like.Accordingly, a first surface of each spacer includes a first surfacearea which possesses static cling or electrostatic adheringcharacteristics for adhering each spacer to an associated lite, but anadjacent second surface area is covered by a thin tab of nonadheringmaterial, such as thin paper, which prevents such adherence. Thus, eachspacer is electrostatically adhered to the lite at its first surfacearea, yet can be readily removed by grasping the second surfacearea/tab. Spacer transfer between stacked lites is prevented by coatingeach spacer opposite second surface with a U.V. coating or itsequivalent which kills or suppresses static and prevents spacer transferbetween adjacent stacked lites.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front schematic perspective view of a pair of relativelyidentical machines, and illustrates each machine feeding a ribbon or acarrier having adhered thereto relatively thin spacers for theindividual transfer of the thin spacers to upper surfaces of lites.

FIG. 2 is a side schematic elevational view of one of the two machinesof FIG. 1, and illustrates the manner in which the ribbon and thinspacers are fed along a first path of travel toward a merger area atwhich the thin spacers are transferred to upper surfaces of lites fedalong a second path of travel.

FIG. 3 is an enlarged fragmentary longitudinal cross-sectional view ofthe merger area between the paths of travel of the ribbon and spacersand the lites, and illustrates one of the spacers being transferred toan upper surface of a lite at a predetermined position relative to theleading edge of the lite as the lite travels from right-to-left.

FIG. 4 is an enlarged fragmentary longitudinal cross-sectional view ofthe merger area between the paths of travel of the ribbon and spacersand the lites, and illustrates a second spacer being transferred fromthe ribbon to the upper surface of the same lite as that illustrated inFIG. 3 but in specified relationship to a trailing edge of the literelative to the direction of travel.

FIG. 5 is a top plan view of the lite of FIGS. 3 and 4, and illustratesthe spacers upon an upper surface of the lite, and graphics and printing(upside down and backwards) upon the upper surface of the lite.

FIG. 6 is a top plan view of the lite of FIG. 5, and illustrates theopposite lower surface of the lite after the lite in FIG. 5 has beenoriented lower side up.

FIG. 7 is a fragmentary enlarged front elevational view of the ribbon orcarrier from which each relatively thin spacer is removed, andillustrates a plurality of circular cut lines each defining asubstantially circular spacer and in parallel broken lines a dark barfor sensor activation and attendant spacer-to-lite application purposes.

FIG. 8 is an enlarged cross-sectional view taken along line 8—8 of FIG.7, and illustrates a first surface of one of the spacers in contact witha first surface of a second strip with a first surface area of thespacer being in adhesive adhering contact with the second strip and asecond surface area of the spacer being in nonadhering contact with thesecond strip.

FIG. 9 is a bottom view of the first surface of one of the thin circularspacers, and illustrates a relatively large first adhering surface area,and a relatively smaller nonadhering second surface area.

FIG. 10 is a fragmentary perspective diagrammatic view of a stack oflites, and illustrates each lite carrying a pair of thin spacers witheach pair of thin spacers separating and protecting adjacent litessupported upon a pallet and wrapped in polymeric/copolymeric film.

FIG. 11 is a fragmentary top plan view of another ribbon constructed inaccordance with this invention, and illustrates indicia (“PEEL HERE”)applied to a surface of a first narrow strip of static cling vinylmaterial and dark printed timing bars of indicia applied to an oppositesurface of an underlying paper strip.

FIG. 12 is a fragmentary longitudinal cross-sectional view through theribbon of FIG. 11, and illustrates the static cling vinyl strip and thepaper strip in first-surface to first-surface adhering relationship overthe entire abutting surfaces thereof.

FIG. 13 is a fragmentary top plan view of the ribbon or carrier of FIG.11, and illustrates the latter after circular die cuts have been madethrough the vinyl cling strip and smaller tab-forming die cuts have beenmade through the paper strip in the area beneath the “PEEL HERE”indicia.

FIG. 14 is a fragmentary top plan view of the ribbon or carrier of FIG.13, and illustrates the reverse side thereof with the tab-forming diecuts forming a paper tab immediately adjacent each dark printed timingbar.

FIG. 15 is an enlarged fragmentary perspective view of the merger areaof FIGS. 3 and 4, and illustrates one of the relatively thin circularspacers of the ribbon of FIGS. 13 and 14 being applied to a lite.

FIG. 16 is a top plan view of the lite of FIG. 15, and illustrates twoof the thin spacers of FIG. 15 applied to an upper surface of the litewhich also includes reverse printing.

FIG. 17 is a highly enlarged cross-sectional view taken generally alongline 17—17 of FIG. 16, and illustrates the “PEEL HERE” minor surfacearea or portion of the spacer in nonadhering relationship to the liteand the major surface area or portion of the spacer in electrostaticadhered relationship to the upper surface of the lite.

FIG. 18 is a schematic side elevational view of another machineconstructed in accordance with this invention, and illustrates themanner in which thin spacers are applied to a lower surface of litesmoving from right-to-left which results in the thin spacers beingapplied to the surface opposite that illustrated in FIGS. 3, 4, 5, and 6of the drawings.

FIG. 19 is a highly enlarged schematic longitudinal cross-sectional viewof an area of merger between the paths of travel of the lite and thespacers of the machine of FIG. 18, and illustrates a gap betweenadjacent conveyor rollers for accommodating transfer mechanisms of thespacer applying machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A machine 10 is illustrated in FIG. 1 of the drawings adjacent asubstantially identical machine 12 which are conventionally supportedabove a conveyor 13 having a plurality of conveyor rollers 14 driven toconvey or feed a plurality of identical lites (glass sheets or plates) Lin a first direction along a first path of travel which in FIG. 2 isfrom right-to-left and is generally designated by the headed arrow T. Asis best illustrated in FIG. 1, the lites, sheets or plates L are of asubstantially rectangular configuration, and though illustrated as beingsubstantially the same size, the lites L associated with the machine 10can be larger or smaller than the lites L associated with the machine12. Alternately, a relatively large lite spanning the width of theconveyor 13 can be fed along the path of travel T and each suchrelatively large single lite can be operated upon by both of themachines 10, 12. However, for the purposes of this description, themachine 10 will be described in association with the lites L associatedtherewith (FIG. 1), and the description thereof is equally applicable tothe substantially identical machine 12, whether the machine 12 operatesindividually upon individual lites L or collectively with the machine 10simultaneously upon a single lite.

Reference is made to FIGS. 5 and 6 of the drawings in which isillustrated one of the lites L which is of a generally rectangularconfiguration defined by an upper surface U_(S) (FIG. 5), a lowersurface L_(S) (FIG. 6), side edges S1, S2, a leading edge E_(l) and atrailing edge E_(t). The direction of travel T of the lites L throughthe machine 10 has been superimposed upon the lite L in FIGS. 5 and 6for reasons which will be more apparent hereinafter. The upper surfaceU_(S) of each lite L includes indicia, designs and/or verbiage orprinting I, such as the backward silkscreened words “TEMPERED GLASS”thereon, as well as appropriate designs (parallel lines) which can varydepending upon the particular end use application of the lites L. In thepreferred embodiment of the invention, each lite L is preferablyconstructed from tempered glass and its end use is as a substantiallyhorizontally oriented shelf in, for example, a refrigerator or the like.Thus, in keeping with the first embodiment of the invention relative tothe machines 10 and 12, the sheets, plates or lites L are fed in thedirection T (FIG. 5) with the upper surface U_(S) uppermost, but in enduse applications the lower surface L_(S) during manufacture becomes theupper surface in end use applications (FIG. 6).

The machine 10, as well as the machine 12, is a modified automatic labelapplicator of the type manufactured by Autolabe, a division of BoothManufacturing Company of 3101 Industrial Avenue Two, Fort Pierce, Fa.34946, and appropriately modified in keeping with the present invention.

As is best illustrated in FIG. 2 of the drawings, the machine 10includes a conventionally supported shaft 21 upon which is removablymounted a reel 22 which is identical to a back-up or reserve reel 23supported upon a shaft 24. Wound upon the reel 22 is a continuous ribbonor carrier 20 of relatively indeterminate length which will be describedimmediately hereinafter. The ribbon 20 is drawn over an idler roll 25freely rotatable on a shaft (unnumbered) carried by an arm 26 which isbiased by a spring (not shown) to provide appropriate tension to theribbon 20. The ribbon 20 passes over another idler back-up roll 27 andis biased thereagainst by a spring 28. A pair of conventionalphotoelectric sensors 30, 31 are disposed on opposite sides of theribbon 20. The photoelectric sensors 30,31 include a conventional lightsource 30 and a conventional light sensor 31 responsive to the presenceor absence of light ribbon 20 and lite L timed feeding under the controlof a conventional solid state computer C. The sensors 30, 31 and thecomputer C are available from Autolabe and other sources. The ribbon 20is partially entrained about an idler roller 32, passes over a guide bar33 and subsequently is partially entrained about a sharp radiused nose34 of a transfer bar 35 in an area of merger A between the path oftravel T of the lites L and a path of travel T1 (FIG. 2) of a portion ofthe carrier 20 as it moves from right-to-left in FIG. 2 toward an areaof merger A. The ribbon or carrier 20 carries a plurality of identicalrelatively thin circular spacers 50 which will be described hereinafter,and at the merger area A individual spacers 50 are removed from theribbon 20 and are transferred to the upper surface U_(S) of each lite L.

After each spacer 50 has been removed from the carrier 20 and has beenapplied to an associated lite L, the ribbon 20 continues travelling overa timed intermittently driven drive roller 36, idler rollers 37, 38, acontinuous driven drive roller 40 and is eventually fed into a trashcontainer 42 through a discharge pipe 41 under the influence of airblown into the discharge pipe 41 by a blower motor 43 via a duct 44. Aspring-biased arm 45 biases a back-up roller 46 against the ribbon 20 tomaintain the ribbon 20 taut whether being fed or stationary. When theribbon 20 is stationary, the roller 40 simply slips against the surfaceof the ribbon 20.

A front edge sensor 47 and a rear edge sensor 48 are positioned in themerger area A and respectively detect the leading edge E_(l) and thetrailing edge E_(t) of each lite L with appropriate signals therefrombeing fed to the computer C for step-advancing the ribbon 20 through theintermittently driven drive roller 36 to successively apply the spacers50 adjacent the leading edge E_(l) and the trailing edge E_(t) of eachlite L. The sensors 47, 48 are preferably light sensors, such as theconventional sensors 30, 31, and preferably the sensors 47, 48 can bemoved in a conventional manner individually to the left or right alongthe path of travel T to selectively vary the positions at which thespacers 50 are applied to the lites L.

During the transfer of each spacer 50 in the area of merger A, bristlesof a brush 19 fixed appropriately adjacent the transfer bar 35 assuresthat each spacer 50 is forcefully adhered to the upper surface U of eachlite L.

In FIGS. 7 and 8 of the drawings, a portion of the ribbon or carrier 20is illustrated which initially includes a first relatively narrow stripof material 21 shown only in FIG. 7 and a second relatively narrow stripof material 22 (FIG. 8). In this embodiment of the invention, bothstrips 21, 22 are relatively translucent paper material of identicalwidth with first surfaces thereof in abutting, contacting, substantiallyadhering relationship to each other. The first strip of material 21includes a plurality of circular cut lines 23 extending substantiallycompletely therethrough with each cut line 23 defining one of therelatively thin and flat spacers 50. The cut lines 23 are die cutsformed in a conventional manner, and once thus formed, a waste ribbonportion 24 (FIG. 7) is entirely removed from the second strip 22 leavingonly the spacers 50 upon the second strip of material 22 (FIG. 8). Thus,in the final ribbon 20 (FIGS. 2 and 8), first strip portions or spacers50 are retained upon the second strip 22 while the second strip portionor the waste strip portion 24 is removed.

Prior to uniting the first and second strips 21, 22, respectively, toeach other, a first surface area 51 (FIG. 9) of each first strip portionor spacer 50 is provided with adhesive characteristics, such as low bondstrength adhesive A₁. Typically, such adhesives AR are commonly used onPost-its notes manufactured by 3M Corporation of st. Paul, Minn. Theadhesive A₁ covers essentially the entire first or major surface area 51of each spacer 50, while an adjacent minor surface area 52 separatedfrom the first major surface area 51 by a line of demarcation 53 (FIGS.8 and 9) lacks adhesive characteristics and possesses substantiallynonadhering characteristics. As is best illustrated in FIG. 8, the lowbond strength adhesive A₁ adheres each spacer 50 to the opposing surfaceof the second strip 22 at the major surface area 51, but the secondsurface area or minor surface area 52 is in nonadhering contact with thesecond strip 22. An upper surface 54 of each spacer 50 has also printedthereupon “PEEL HERE” or similar indicia for a purpose to be describedmore fully hereinafter.

A plurality of means 55 (FIGS. 7 and 8) are spaced from each other alongthe second strip 22 for detection by the sensors 30, 31 to effect timedremoval of each spacer 50 from the ribbon 20 specifically from thesecond strip 22 in the area of merger A (FIGS. 2, 3 and 4). The means 55are a plurality of black printed bands through which light essentiallywill not pass, whereas light will pass through the reminder of theribbon 20 because of the relatively thin and translucent characteristicsof the paper of the second strip 22 and the spacers 50.

Reference is made specifically to FIGS. 2, 3 and 4 of the drawings whichcollectively illustrate the manner in which two of the spacers 50, 50(FIGS. 5 and 6) are applied to the upper surface U_(S) of each of thelites L. As the lites L continuously travel from right-to-left in FIG. 2along the path of travel T, the leading edge E_(l) (FIG. 3) of a lite Lwill be sensed by the sensor 47 which is hardwired to the computer C.The computer C in turn signals a conventional drive mechanism D torotate the drive roller 36 clockwise and thereby advance the tape 20 inthe direction T₁. During this advancement, the very sharp or abrupt nose34 of the transfer bar 35 creates an abrupt bend in the second strip 22(FIG. 3), but the spacer 50 continues moving along the path T₁ towardand upon the upper surface U_(S) of the lite L under the wiping actionof the bristles of the brush 19 somewhat downstream from the leadingedge E₁ of the lite L. The latter is a relatively abrupt and shortadvancement of the ribbon 20 because the next black timing bar 55passing between the sensors 30, 31 transmits a signal to the computer Cand the latter in turn signals the drive mechanism D to stop the driverotation of the drive roller 36 which ceases advancement of the ribbon20 in the direction T₁. As the trailing edge E_(t) of the lite L is nextsensed by the sensor 48, a signal is again transmitted to the computer Cwhich in turn causes the step-advancement of the ribbon 20 via the drivemechanism D and the drive roller 36 during which the next succeedingspacer 50 (FIG. 4) is applied to the upper surface U_(S) of the samelite L upstream, as viewed in the direction of travel T, from thetrailing edge E_(t). The feed of the second spacer 50 is also short andabrupt and is terminated upon the next succeeding black timing bar 55passing between the sensors 30, 31 to again stop feed of the ribbon 20via the computer C, the drive mechanism D and the drive roller 36. Thissequence is repeated for each successive lite L, and the unending seriesof stop-and-go advancements of the ribbon 20 controlled by the sensors30, 31 and 47, 48 apply the spacers 50 in spaced pairs to each uppersurface U_(S) of each lite L in the manner best illustrated in FIGS. 5and 6 of the drawings.

A group or stack of the lites L is designated by the reference characterG in FIG. 10, and the plurality of lites L thereof are each maintainedin separated spaced relationship by the spacers 50 therebetween. Thisgroup or stack G of lites L are preferably supported upon a conventionalpallet S and are conventionally overwrapped in relatively strongpolymeric/copolymeric wrapping material W and are thus transported to acustomer for end use manufacturing or installation purposes andsubsequent retail end use. For example, if the stack or group G ofspaced lites L are sent to a refrigerator manufacturer, the wrapping Wwould be removed, the spacers 50, 50 of each lite L would be removed,and the lites L installed, as, for example, refrigerator shelves. Thenonadhering surface area 52 (FIGS. 8 and 9) of each spacer 50 provides areadily and easily grasped area/portion which is additionally identifiedby the words “PEEL HERE” (FIGS. 5 and 6). Therefore, each non-adheredportion 52 of each spacer 50 can be readily grasped and pulled toquickly and readily remove the spacers 50 from the lites L.

It is important to recognize that the uppermost surface 54 of eachspacer 50 opposite the surface areas 51, 52 lacks any adhering oradhesive characteristics. In other words, the upper surface 54 of eachspacer 50 possesses nonadhering characteristics and when the stack G isunwrapped, the lites L will not only readily separate one from another,but the spacers 50 will assuredly remain positioned as applied, namely,two spacers 50 per only each upper surface U_(S) of each lite L absentthe transfer of any spacer 50 to opposite abutting surfaces L_(S) ofadjacent lites L. Absent the latter, subsequent end users would beconfronted with the problem of removing the spacers 50 from both upperand lower surfaces, U_(S), L_(S), respectively, of each lite L, ratherthan from the single surface U_(S) which is more user friendly and lesstime-consuming. Though the spacers 50, 50 are mildly adhesively adheredto the upper surface U_(S) of the lites L, it should be noted that thespacers 50, 50 and the backward silk screened indicia I are on the sameupper side U_(S) of each lite L, but in the end use position (FIG. 6) ofeach lite L, the lite L must be installed lower side L_(S) up (FIG. 6)to render the indicia I readable. When the spacers 50, 50 are removedfrom each lite L prior to installation into a refrigerator, for example,there is no particular problem presented by the upper surface U_(S)location of the spacers 50, 50. However, if the spacers 50, 50 are notremoved and the lites L are installed as shelves, the now upper surfaceU_(S) faces down and can present spacer removal problems, mostsignificant of which is the cumbersome and awkward manipulative removalof the spacers 50 from below. The latter problem is effectively solvedin a manner to be described subsequently with respect to FIGS. 18 and 19of the drawings.

Reference is, however, first directed to another ribbon or carrierillustrated in FIGS. 11 through 14 of the drawings which is generallydesignated by the reference numeral 60. The ribbon 60 includes a firstrelatively narrow strip 61 of substantially translucentpolymeric/copolymeric plastic material having static cling orelectrostatic characteristics, such as conventional static cling vinyl,and a second relatively narrow strip 62 of substantially translucentpaper material with respective first surfaces 63, 64 thereof being inabutting relatively weakly adhering relationship to each other. Thestrips 61, 62 adhere to each other by precoating the surface 64 of thepaper strip 62 with an extremely weak bonding adhesive (not shown), suchas the adhesive Al used in association with the spacers 50 (FIGS. 8 and9). The adhesive Al is identical to that earlier described relative toadhesive used upon Post-its notes manufactured by 3M Corporation of St.Paul, Minn. Opposite second surfaces 65, 66 of the respective strips 61,62 carry respective indicia 67, 68. The indicia 67 are the words “PEELHERE,” or any equivalent thereof, though the indicia 67 need notnecessarily be utilized in conjunction with the utilization of theribbon 60. The indicia or timing stripes 68, however, constitute aplurality of means spaced from each other along the second surface 66 ofthe strip 62 which cooperate with the sensors 30, 31 (FIG. 2) to stopribbon feed shortly after each spacer 50 has been applied to each lite Lin response to the successive operation of the sensors 47, 48, as wasdescribed earlier herein. The timing strips or sensor-activating means68 are relatively broad black printed stripes which block lighttransmission through the relatively translucent material of the strips61, 62.

The first strip 61 also includes a plurality of continuous circular diecut lines 69 (FIGS. 11 and 12) setting-off equally spaced successivefirst strip portions or spacers 70 of a circular configuration. As isbest illustrated in FIG. 13, each dark timing stripe 68 is diametricallylocated relative to an associated spacer 70. The material of the strip61 surrounding the spacers 70 is generally designated by the referencenumeral 71 (FIG. 13) and constitutes a second strip portion or a wastestrip portion of the strip 61 which is entirely removed incident to theutilization of the ribbon 60 in conjunction with the machines 10, 12, asis best illustrated in FIG. 15 of the drawings.

The strip 62 also includes a plurality of equally spaced successive diecut lines 72 (FIG. 14) defining relatively small tabs 80. Each cut line72 includes an arcuate cut line portion 73, opposite parallel relativelyshort cut line portions 74, 75, and a cut line portion 76 adjacent andgenerally parallel to its associated dark timing stripe or bar 68. Eachtab 80 underlies the “PEEL HERE” indicia 67, as is best viewed in FIG.13.

The ribbon 60 of FIGS. 13 and 14 with the waste strip portion 71 removedis wound upon a reel, such as the reel 22 of FIG. 2, and is threadedthrough the various components of the machine 10 identically asillustrated in FIG. 2 with respect to the ribbon 20. The overalloperation of the machine 10 in conjunction with the ribbon 60 remainsessentially the same as that heretofore described with respect to theribbon 20. In this case the ribbon or carrier 60 is preferably woundupon the reel 22 such as the “PEEL HERE” portions of the spacers 70 aretrailing as they approach the merge area A in the manner shown in FIG.15 and are progressively stripped therefrom in the manner heretoforedescribed in detail relative to the ribbon 20. However, due to thestatic cling characteristics of the static cling vinyl material, eachnegatively charged vinyl spacer 70 is attracted to the positivelycharged lite L and electrostatically adheres/statically clings thereto.During the application of each spacer 70, as is best illustrated in FIG.15, the small tab 80 associated therewith is also removed from the strip62. Since the tab 80 is made of paper, it prevents the overlying portionof each spacer 80 from electrostatically adhering or clinging to thelite L, as is best illustrated in FIG. 17 of the drawing. Accordingly,the spacers 70 can be readily removed by simply gripping the “PEEL HERE”areas or portions 80, pulling the same and removing the spacers 70 fromthe lites L.

Though the ribbon 60 is illustrated in FIG. 15 with the “PEEL HERE”edges of each spacer 70 trailing, the ribbon 60 can be reversed upon thereel 22 such that it would be unwound with the “PEEL HERE” portion ofeach spacer leading in the direction of ribbon and lite travel, T₁ andT, respectively. In such case, the application of each spacer 70 to eachlite L remains essentially the same as that heretofore described.Therefore, whether the “PEEL HERE” portion and small tab 80 of eachspacer 70 is leading or trailing at the merge area A, the sharp nose 34of the transfer bar 35 initiates separation of the spacers 70 from thestrip 62 of the carrier 60 along with the tabs 80 thereof. Furthermore,as in the case of the lites L of FIGS. 5 and 6, the spacers 70 are alsopositioned upon the upper surface U_(S) of the lite L of FIGS. 16 and 17which is, of course, the lower side of the end use position of the liteL, noting the reverse and backward printing I of “TEMPERED GLASS” inFIG. 16.

The lites L of FIG. 16 are stacked in the manner heretofore describedrelative to FIG. 10 and, thus, are protected against scratching,cracking, etc. during shipment due to the spacing afforded adjacentplies L by the spacers 70.

Another machine constructed in accordance with this invention isillustrated in FIG. 18 of the drawings, and identical components areidentically numbered and primed with the overall machine beingdesignated by the reference numeral 10′.

The machine 10′ differs in one major aspect from the machines 10, 12,namely, the machine 10′ is located beneath a conveyor 13′. The drivenrollers 14′ of the conveyor 13′ feeds the lites L′ from right-to-leftalong a path of travel designated by the headed arrow T′. One or more ofthe rollers 14′ are eliminated at the area of merger A′ between the pathof travel T′ of the lites L′ and the path of travel T′₁ of the ribbon60′ and the spacers 70′. This allows the transfer bar 35′ and the brush19′ to cooperate in the manner heretofore described relative to themachine 10 to transfer the spacers 70′ to the lower surface L′_(S) ofeach lite L′ in the manner most readily apparent from FIG. 19 of thedrawings. Therefore, in this manner the spacers 70′ from the ribbon orcarrier 60′ (or the spacers 50 from the ribbon or carrier 20) can beselectively and successively applied to the lower surface L′_(S) of eachof the lites L′ during the travel thereof. The importance of applyingthe spacers 50, 70 to the lower surface L′_(S) of the lites L is therelationship thereof to the printed material or design indicia I appliedto and carried by each of the lites L, L′, such as the parallel designlines and the phrase “TEMPERED GLASS” appearing adjacent the leadingedges E_(l) of the lites L, L′. This is particularly important if an enduse manufacturer does not, for example, remove the spacers 70′ andinstalls the lites L′ in, for example, a refrigerator for utilization asa horizontal shelf. The end user manufacturer/purchaser in the case ofthe spacers 20 of FIG. 6 would have to reach beneath the lite or shelf Land remove the spacers 20 from the underside because, of course, themanufacturer/purchaser would install the lite or shelf L of FIG. 6 withthe lower surface L_(S) uppermost such that the design and the wordingindicia I “TEMPERED GLASS” are properly oriented. Bottom surface removalof the spacers 20 or 70 or 70′, etc. could be cumbersome, as notedearlier, but removal from the in-use upper surface U's would berelatively straightforward. Accordingly, thought the machine 10′ appliesthe spacers 50, 70, 70′, etc. heretofore described to the lower surfacesL's of the lites L′ during production, in end use applications thesespacers are located at the more accessible top surfaces of the lites L′and can be more readily removed therefrom.

As was described heretofore, the static cling vinyl spacers 70 areadhered to the lites L and stacked in the manner heretofore describedrelative to the spacers 50 of FIG. 10. However, the spacers 70 at timesmight transfer from the surface of the lite L to which they werespecifically applied to the surface of an adjacent lite L, particularlyif the wrap W is relatively tight, as it must be to avoid scratching,breakage, etc. Should such unintended spacer transfer occur, theadjacent “transferee” lite might have, for example, two spacers 70, 70on one surface, a single spacer on the opposite surface, and adjacent“transferor” spacer would have only one spacer on the opposing surface.However, in further accordance with this invention, such inadvertenttransfer of static cling vinyl spacers 70 from the upper surface U_(S)of one lite L to the adjacent lower surface L_(S) of a next adjoiningstacked lite is prevented from occurring by applying coating means orequivalent means upon the upper surface 65 (FIGS. 11 and 12) of thevinyl cling strip 61 after the indicia 67 has been applied thereto. Oneexample of such means is a coating of ultraviolet material which issurface coated over the entire surface 65 and cured by an ultravioletlight. This “kills” or suppresses the static properties of the surface65 and thus keeps each spacer 70 from transferring from the intendedlite (FIG. 17) to the adjacent lite which it abuts when stacked in themanner illustrated in FIG. 10. Obviously, since the pairs of spacersadhered to the upper surface U_(S) of each lite L remain adhered theretoand do not transfer to the lower surfaces L_(S) of an adjacent lite, thelites easily separate and, of course, spacers need but be removed from asingle surface during end use applications.

In lieu of the ultraviolet coating, enamel paint or a water-basedcoating, suitably dried, can be applied over the surface 65 (FIGS. 11and 12) thereby preventing the unintended transfer of the spacer 70.

Although a preferred embodiment of the invention has been specificallyillustrated and described herein, it is to be understood that minorvariations may be made in the apparatus without departing from thespirit and scope of the invention, as defined the appended claims.

We claim:
 1. A stack of sheets comprising a plurality of sheets eachhaving opposite first and second surfaces and a peripheral edge, aplurality of relatively spaced substantially thin flat spacers eachhaving first and second opposite surfaces, adjacent first and secondsurface areas of the first surface of at least one of said spacers beingrespectively adhered to and nonadhered to the first surface of eachsheet, said nonadhered second area including a peripheral edge portionof said at least one spacer, the second surface of said at least onespacer being in abutment with the second surface of an adjacent sheetwhereby said sheets are maintained in adjacent slightly spacedprotective relationship with each other, and means binding the pluralityof sheets together in a stack.
 2. The stack of sheets as defined inclaim 1 wherein said sheets are glass and said spacers are static clingvinyl.
 3. The stack of sheets as defined in claim 1 wherein said sheetsare glass and said spacers are paper.
 4. The stack of sheets as definedin claim 1 wherein said sheets are glass and said spacers are adhesivebacked paper.
 5. The stack of sheets as defined in claim 1 wherein atleast said second surface of said at least one spacer includes means forpreventing spacer transfer between adjacent sheets.
 6. The stack ofsheets as defined in claim 1 wherein said sheets are glass and saidspacers are adhesively backed paper dots.
 7. The stack of sheets asdefined in claim 1 wherein said sheets are glass and said spacers areadhesively backed substantially circular paper dots.
 8. The stack ofsheets as defined in claim 1 including means for adhering said firstsurface area of each spacer to each sheet first surface, and means forpreventing said second surface area of each spacer from adhering to eachsheet first surface.
 9. The stack of sheets as defined in claim 8wherein said adhering means include adhesive characteristics.
 10. Thestack of sheets as defined in claim 8 wherein said adhering meansinclude static cling characteristics.
 11. The stack of sheets as definedin claim 8 wherein said first surface area constitutes a major surfacearea of each spacer.
 12. The stack of sheets as defined in claim 8wherein said adhering means include a substantially low adhesivestrength adhesive.
 13. The stack of sheets as defined in claim 8 whereinsaid preventing means is a nonadhering covering upon said second surfacearea.
 14. The stack of sheets as defined in claim 8 wherein saidadhering means is upon said first and second surface areas, and saidpreventing means overly said adhering means at said second surface area.15. The stack of sheets as defined in claim 8 wherein said first andsecond surface areas include said adhering means, and said preventingmeans overly said adhering means at said second surface area.
 16. Thestack of sheets as defined in claim 8 wherein said adhering means isupon said first and second surface areas, said preventing means overlysaid adhering means at said second surface area, and said adhering meansinclude adhesive characteristics.
 17. The stack of sheets as defined inclaim 8 wherein said adhering means is upon said first and secondsurface areas, said preventing means overly said adhering means at saidsecond surface area, and said adhering means include static clingcharacteristics.
 18. The stack of sheets as defined in claim 8 whereinsaid adhering means is upon said first and second surface areas, saidpreventing means overly said adhering means at said second surface area,and said adhering means include an adhesive.
 19. The stack of sheets asdefined in claim 8 wherein said adhering means is upon said first andsecond surface areas, said preventing means overly said adhering meansat said second surface area, and said preventing means is a nonadheringcovering upon said second surface area.
 20. The stack of sheets asdefined in claim 8 wherein said first and second surface areas includesaid adhering means, said preventing means overly said adhering means atsaid second surface area, and said adhering means include static clingcharacteristics.
 21. The stack of sheets as defined in claim 8 whereinsaid first and second surface areas include said adhering means, saidpreventing means overly said adhering means at said second surface area,said adhering means include static cling characteristics, and saidpreventing means is a nonadhering covering upon said second surfacearea.
 22. The stack of sheets as defined in claim 8 wherein said firstand second surface areas include said adhering means, said preventingmeans overly said adhering means at said second surface area, saidadhering means include static cling characteristics, and said preventingmeans is a nonadhering paper covering upon said second surface area.